Visual information processing of schizotypics : a backward masking procedure

The present study investigated early visual information processing of individuals whose Minnesota Mutiphasic Personality Inventory (MMPI-168) profiles indicated schizophrenic tendencies in the absence of an obvious thought disorder. These schizotypic individuals were identified by the 2-7-8 M PI code type and were compared on a visual backward masking task with three other groups: an "Inflation-free" group, an "Other-inflations" group, and a group with an "8-9" MMPI code. The 2-7-8 and the 8-9 groups had significantly fewer correct identifications of target stimuli than either the Inflation-free group or the Other-inflations group. The 2-7-8 group had significantly higher Critical Stimulus Durations (CSD) than either the Inflation-free group or the 8-9 group. These results suggest that both the 2-7-8 group and the 8-9 group are more vulnerable to the effects of the masking stimulus. Schizophrenics have demonstrated similar susceptibility to masking stimuli. It is suggested that both the 2-7-8 and the 8-9 M I profile code may be an index of vulnerability to schizophrenia.